Climate fluctuations and the spring invasion of the North Sea by Calanus finmarchicus

Michael R. Heath, Jan O. Backhaus, Katherine Richardson, Eddie McKenzie, Dag Slagstad, Douglas Beare, John Dunn, John G. Fraser, Alejandro Gallego, Dagmar Hainbucher, Stephen Hay, Sigrun Jonasdottir, Heather Madden, John Mardaljevic, Andreas Schacht, European Union - MAS2-CT94-0085 (Funder)

Research output: Contribution to journalArticle

98 Citations (Scopus)

Abstract

The population of Calanus finmarchicus in the North Sea is replenished each spring by invasion from an overwintering stock located beyond the shelf edge. A combincation of field observations, statistical analysis of Continuous Plankton Recorder (CPR) data, and particle tracking model simulations, was used to investigate the processes involved in the cross-shelf invasion. The results showed that the main source of overwintering animals entering the North Sea in the spring is at depths of greater than 600m in the Faroe Shetland Channel, where concentrations of up to 620m -3 are found in association with the overflow of Norwegian Sea Deep Water (NSDW) across the Iceland Scotland Ridge. The input of this water mass to the Faroe Shetland Channel, and hence the supply of overwintering C. finmarchicus, has declined since the late 1960s due to changes in convective processes in the Greenland Sea. Beginning in February, animals start to emerge from the overwintering state and migrate to the surface waters, where their transport into the North Sea is mainly determined by the incidence of north-westerly winds that have declined since the 1960s. Together, these two factors explain a high proportion of the 30-year trends in spring abundance in the North Sea as measured by the CPR survey. Both the regional winds and the NSDW overflow are connected to the North Atlantic Oscillation Index (NAO), which is an atmospheric climate index, but with different time scales of response. Thus, interannual fluctuations in the NAO can cause immediate changes in the incidence of north-westerly winds without leading to corresponding changes in C. finmarchicus abundance in the North Sea, because the NSDW overflow responds over longer (decadal) time scales.
LanguageEnglish
Pages163-176
Number of pages13
JournalFisheries Oceanography
Volume8
Issue numbers1
DOIs
Publication statusPublished - Sep 1999

Fingerprint

Calanus finmarchicus
North Sea
overwintering
climate
deep water
plankton
North Atlantic Oscillation
seawater
westerly
water
incidence
timescale
Iceland
Greenland
animal
Scotland
shelf break
simulation models
animals
surface water

Keywords

  • calanus finmarchicus
  • circulation
  • modelling
  • north atlantic
  • aorth atlantic oscillation index
  • norwegian sea
  • deep water
  • plankton
  • winds

Cite this

Heath, M. R., Backhaus, J. O., Richardson, K., McKenzie, E., Slagstad, D., Beare, D., ... European Union - MAS2-CT94-0085 (Funder) (1999). Climate fluctuations and the spring invasion of the North Sea by Calanus finmarchicus. Fisheries Oceanography, 8(s1), 163-176. https://doi.org/10.1046/j.1365-2419.1999.00008.x
Heath, Michael R. ; Backhaus, Jan O. ; Richardson, Katherine ; McKenzie, Eddie ; Slagstad, Dag ; Beare, Douglas ; Dunn, John ; Fraser, John G. ; Gallego, Alejandro ; Hainbucher, Dagmar ; Hay, Stephen ; Jonasdottir, Sigrun ; Madden, Heather ; Mardaljevic, John ; Schacht, Andreas ; European Union - MAS2-CT94-0085 (Funder). / Climate fluctuations and the spring invasion of the North Sea by Calanus finmarchicus. In: Fisheries Oceanography. 1999 ; Vol. 8, No. s1. pp. 163-176.
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Heath, MR, Backhaus, JO, Richardson, K, McKenzie, E, Slagstad, D, Beare, D, Dunn, J, Fraser, JG, Gallego, A, Hainbucher, D, Hay, S, Jonasdottir, S, Madden, H, Mardaljevic, J, Schacht, A & European Union - MAS2-CT94-0085 (Funder) 1999, 'Climate fluctuations and the spring invasion of the North Sea by Calanus finmarchicus' Fisheries Oceanography, vol. 8, no. s1, pp. 163-176. https://doi.org/10.1046/j.1365-2419.1999.00008.x

Climate fluctuations and the spring invasion of the North Sea by Calanus finmarchicus. / Heath, Michael R.; Backhaus, Jan O.; Richardson, Katherine; McKenzie, Eddie; Slagstad, Dag; Beare, Douglas; Dunn, John; Fraser, John G.; Gallego, Alejandro; Hainbucher, Dagmar; Hay, Stephen; Jonasdottir, Sigrun; Madden, Heather; Mardaljevic, John; Schacht, Andreas; European Union - MAS2-CT94-0085 (Funder).

In: Fisheries Oceanography, Vol. 8, No. s1, 09.1999, p. 163-176.

Research output: Contribution to journalArticle

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AU - Heath, Michael R.

AU - Backhaus, Jan O.

AU - Richardson, Katherine

AU - McKenzie, Eddie

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AU - Beare, Douglas

AU - Dunn, John

AU - Fraser, John G.

AU - Gallego, Alejandro

AU - Hainbucher, Dagmar

AU - Hay, Stephen

AU - Jonasdottir, Sigrun

AU - Madden, Heather

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KW - calanus finmarchicus

KW - circulation

KW - modelling

KW - north atlantic

KW - aorth atlantic oscillation index

KW - norwegian sea

KW - deep water

KW - plankton

KW - winds

U2 - 10.1046/j.1365-2419.1999.00008.x

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